1. The Field of the Invention
The present invention relates to wireless networks, and more specifically, to a wireless device making roaming decisions based on association qualities between the wireless device and one or more wireless access points.
2. Background and Relevant Art
Computer systems and related technology affect many aspects of society. Indeed, the computer system's ability to process information has transformed the way we live and work. Computer systems now commonly perform a host of tasks (e.g., word processing, scheduling, and database management) that prior to the advent of the computer system were performed manually. More recently, computer systems have been coupled to one another to form both wired and wireless computer networks over which the computer systems can communicate electronically to share data. As a result, many tasks performed at a computer system (e.g., voice communication, accessing electronic mail, electronic conferencing, web browsing) include electronic communication with one or more other computer systems via wired and/or wireless computer networks.
For example, a number of computer systems can be coupled to a data hub through corresponding wired connections (e.g., category 5 cable) to form a wired network (e.g., an Ethernet segment). Similarly, a number of wireless computer systems (commonly referred to as “stations”) can be coupled to a wireless access point (“AP”) through corresponding wireless connections (e.g., resulting from appropriate communication between radio transmitters and receivers) to form a wireless network (e.g., an IEEE 802.11 network). Further, a data hub and/or an AP can be connected to other data hubs, APs, or other network devices, such as routers, gateways, and switches to form more complex networks (including both wired and wireless connections).
Many wireless network environments include a plurality of stationary access points that provide mobile stations with access to a wired network. A mobile station can associate with one of the access points to gain access to the resources on the wired network. For example, a mobile station can associate with an access point that provides access (potentially through one or more other wired components) to the Internet. Once associated, the mobile station and the access point can wirelessly communicate. Accordingly, the access point essentially operates as an intermediary that compatibly translates wireless communication (e.g., IEEE 802.11) into wired communication (e.g., Ethernet) and vice versa.
However, due to changed conditions, for example, when the mobile station is blocked from a current access point by physical barriers, when the current access point malfunctions, or when the mobile station moves from the vicinity/coverage of the current access point to another access point, communication between the mobile station and the current access point may be degraded or even lost Communication is lost when the signal strength of the access point drops below the receive sensitivity threshold of the mobile station's network interface and thus the mobile station can not receive packets from the current access point. The mobile station may also have a roaming threshold at or near the receive sensitivity threshold.
When signal strength drops below the roaming threshold, the mobile station may attempt to identify other access points that can provide access to the same wired network (commonly referred to as “roaming”). If other access points are identified, the mobile device can attempt to establish a new association with one of the other access points. However, aside from signal strength dropping below a roaming threshold, few, if any, other events typically cause a mobile station to roam. Thus, a mobile station may maintain an association with an access point even though communication with the access point is substantially degraded and other access points are potentially be available.
When a mobile station does roam, the mobile station typically identifies access points based almost solely on the access points being able to provide access the same wired network. However, aside from being able to provide access to the same wired network, mobile stations do not typically distinguish between access points. Accordingly, a mobile station typically does not consider the appropriateness of connections that would result from associating with different access points. For example, a mobile station may associate with an access point that provides a connection having increased latency and/or reduced bandwidth, even though other access points could provide connections with reduced latency and/or increased bandwidth. Therefore, it would be advantageous if stations determined when to roam and when to associate with an access point in a more intelligent manner.